Actuating device for lever-drawbridges



July 5, 1932. F. DuwE" 1,865,621

ACTUATING DEVICE FQRLEVER' DRAWBRIDGES Filed June 18, '1930 In yenZar: L ildllfd Patented July 5, 1932 T in l.

rQATE T OFFICE FRIEDRICH DUWE, OF MAINZ-KASTEL, GERMANY, .ASSIGNOR TO MASGHINENFABRiK AUGSBURG-NURNBERG A. G., OF NUBEMBERG, GERMANY, A CORPORATION OF GER- MA NY ACTUATING DEVICE FOR iEiIEIViER-DR.AVVBIRIDG IES Applicationfiled June 18,1930, Serial 110.1431371, and in Germany June 18, 1929.

- cause of the relatively great amount of space required to accommodate the racks and their supports.

Because of the foregoing and other reasons it has heretofore been proposed to employ actuating means in the form of endless chains or cables which require comparatively less space than rigid racks for their installation.

However, the use of chains or cables is not always possible, and, moreover, chains and cables not only are unsafe but have a tendency to increase in length, with various consequent disadvantages.

Accordingly, the general object of the present invention is to provide an actuating means for lever-drawbridges which retains the desirable features and eliminates the undesirable features of rigid racks and chains or cables as actuating means for such drawbridges.

In the accompanying drawing the figure is a view in side elevation-of a lever-drawbridge equipped with an actuating means construct ed in accordance with one practicable embodiment of the invention.

Referring to the drawing in detail, I) designates a portion of a lever-drawbridge carrying a sector a which is rollable on a horizontal support 0 to raise and lower the drawbridge.

A flexible rack composed of numerous-short length sections (5, d, etc, which are pivotally connected together in end to end relation, is connected by a link or one of the end sections d of the rack to the sector a at the center thereof, and said rack is disposed between spaced guide members and g which are located above and extend parallel to the horizontal surface of the support 6 on which the sector a is rollable, and at a distance fromsaid surface corresponding to the radius of the sector a,whereby longitudinal 'rnovement of the rack between said guide Ymei'nbers' is effective to roll said sector.

" A Windlass conventionally illustrated at z "is mounted on a frame [a and is inclusive of a pinion h coope'rati'ng with the rack to produce longitudinalinovements thereof. This Windlass preferably is located at or near the outer ends of the rack guide. members, and at the side'of the pinion h remote from thesector a the lower guide member 7 is extended downwardly as indicated at f and the upper guide member is terminated short of said downwardly extended portion of the lower guidejmember', whereby, when the rack is moved to the right as viewed in the drawing to efi'ec't raising of thedrawbridge, the rack sections 03", d, etc, after passing the outer enact the guide member f are free topivot "relative to each other and to gravitate down wardly along the extension f as illustrated inthe drawing'by dotted lines. Thus it is 'apparentthat the effective portion of the rack need be no longer than the length of the surface 5 and that the entire actuating means is disposed within 'aspace corresponding in de'sir'able conservation of space, and of a rigid racka's regards the desirable features of this type of actuating means'as compared with a chain or cable, and at the same time avoids the disadvantages inherent to both a rigid rack or a chain or cable actuating means, because the present rack not only is flexible when not confined between the guide members f and 9, but when confined between said 5 guide members is equivalent to a rigid rack. From the foregoing description considered in connection with the accompanying drawing it is believed that the construction, operation and advantages of the invention will be clearly understood. It is pointed out, however, that the structure shown may be modified and that the arrangement of elements may be varied in different respects within the spirit and the scope of the invention as defined in the appended claims.

I claim:

1. In combination with a drawbridge inclusive of a sector, a support having a surface on which the sector is rollable to raise 9 and lower the drawbridge, a rack connected with the sector, said rack being composed of a plurality of rack sections pivotally connected together in end to end relation, elongated guide members between which said rack sections are movable, said guide members being effective to prevent the rack sections disposed therebetween from pivoting relative to each other whereby the rack is operable in tension to raise the drawbridge and :1 in compression to close the same, a pinion engaged with the rack for moving the same longitudinally between said guide members, and means for actuating said pinion.

2. In combination with a drawbridge inclu- 5 sive of a sector, a support having a surface on which said sector is rollable to raise and lower the drawbridge, a rack pivotally connected at one end with the sector at the center thereof, said rack being composed of a plurality of rack sections pivotally connected together in end to, end relation, elongated guide members substantially coextensive in length with the surface of the support over which the sector is rollable and between 5 which said rack sections are confined and held against pivotal movement relative to each other whereby the rack is operable in tension to raise the drawbridge and in compression to close the same, a pinion engaged with the 6 rack for moving the same longitudinally between said guide members thus to effect rolling of said sector to raise or lower the drawbridge, and means for actuating said pinion.

3. In combination with a drawbridge in- 5 elusive of a sector, a support having a surface on which said sector is rollable to raise and lower the drawbridge, a rack pivotally connected at one end with the. sector at the center thereof, said rack being composed of a 9 plurality of rack sections pivotally connected together in end to end relation, elongated guide members substantially coextensive in length with the surface of the support over which the sector is rollable and between which 3 said rack sections are confined and held 

